NASA’s Cassini spacecraft has been observing Saturn since 2004, but mission control has been careful not to get too close to the ringed planet for fear of damaging the probe. Now, Cassini is nearly out of fuel, and it’s time to take some risks. Cassini began altering its trajectory early this week for the “Grand Finale,” a series of orbits that will take the spacecraft closer to Saturn than ever before. The first images from the Grand Finale have been sent back to NASA, and they’re stunning. They’re also just the start — Cassini has 21 more close orbits planned.
Cassini made one last close pass of Saturn’s moon Titan recently, which sent it off on a trajectory that allowed it to pass between Saturn and the innermost ring. The first such orbit was completed late Wednesday and early Thursday. NASA live streamed the Jet Propulsion Laboratory’s mission control room as the team waited on the probe to send back its data. The first unprocessed images were received right on time, and now we’ve got a number of really impressive shots to drool over.
As it dove through the gap, Cassini came within 1,900 miles (3,000 kilometers) of Saturn’s atmosphere. The gap between the rings and Saturn’s cloud layers is only about 1,500 miles (2,000 kilometers), and this is all happening more than a billion miles away. It took careful planning, but it’s paying off. The first dive allowed NASA scientists to get an unprecedented view of the planet, and the images are reportedly even better than the team had hoped.
The image above shows off the incredible “giant hurricane” in Saturn’s atmosphere up at the north pole. This hexagon-shaped storm has been spied from afar, but now we’ve gotten a closer look at the cloud formations around it. NASA is particularly interested in a formation dubbed “little car,” that runs around the perimeter of the hexagon (below). The center of the storm is calm, but little car moves at more than 300 miles per hour.
Farther south, Cassini spotted some unexpected detail in the clouds. The wisps of light above look a bit like electrical activity, but are in fact giant blobs of ammonia floating 93 miles (150 kilometers) above the main cloud layer. Up close, they probably look a lot like the water vapor clouds we have here on Earth.
Cassini will make another swoop past Saturn early next week. The mission will come to an end on September 15th when Cassini finally spirals into Saturn’s atmosphere. It’ll be sending data back for as long as possible before it’s swallowed up.
source : https://www.extremetech.com/extreme/248466-cassinis-first-grand-finale-images-theyre-stunning